417-420 (tr. Stephen Halliwell):
Does he discern some profit in staying here?
Does he believe that living here with me
He'll vanquish foes and benefit his friends?
ὁρᾷ τι κέρδος ἐνθάδ᾽ ἄξιον μονῆς,
ὅτῳ πέποιθ᾽ ἐμοὶ ξυνὼν κρατεῖν ἂν ἢ
τὸν ἐχθρὸν ἢ φίλοισιν ὠφελεῖν ἔχειν;
Nan Dunbar ad loc. (student edition):
The question implies that it is a desirable 'advantage' (κέρδος)
for a man to be able 'to beat his enemy or help his friends'. This represents the traditional Greek idea of justice: cf. the sober statesman Solon's prayer (13.3-6 West) for wealth, good reputation, εἶναι δὲ γλυκὺν ὧδε φίλοις, ἐχθροῖσι δὲ πικρόν, τοῖσι μὲν αἰδοῖον, τοῖσι δὲ δεινὸν ἰδεῖν, Pl. Rep. 332 A.
See Mary Whitlock Blundell, Helping Friends and Harming Enemies: A Study in Sophocles and Greek Ethics
(Cambridge: Cambridge University Press, 1989; rpt. 1991), pp. 26–59.